This is actually pretty much the full version of my summary only I'm calling the imported birds EEs rather than Auracanas since they weren't what we currently know as Auracanas.
The issue I had with your post had to do with the current breeding program. The original imported birds didn't cease to exist when the breeds were created. They just no longer qualified to bear the name "Auracanas" as all blue shell layers were called back then.
Continuing to breed from their landrace stock isn't the same as taking standardized Ameraucanas and crossing them with other breeds.
I'm sorry, I'm not sure what your disagreement is with. Their is no other original land race stock that is used in America to produce EE chicks. What is used in breeding in America are the developed descendant breeds known as the Ameraucana and Araucana. Also used is the hybrid Easter Egger, which can be a mix with either Ameraucana or Araucana, Ameraucana being by far the most common as Araucana is a rare breed in America (due in part to the difficulty to breed them as there is a 25% chick loss due to the lethal tufting gene).
The original imported birds ("landrace" as you refer) were originally called Araucana from the La Araucana region in Chile, dubbed thus by the Spanish in 1556.
The original "landrace" Araucana was not a pure breed itself. It was very much a mixed breed chicken used by the Mapuche Indians. They had 2 lines, a brown laying tailed type and a tufted, rumpless, pea combed blue layer type. Breeding the two produced a crested, bearded, pea combed, tufted bird who laid blue eggs as blue shell and pea comb is dominant. A line was refined by Dr. Bustos in Chile, from which a Professor Costello exhibited photographs at the Santiago Exhibition in 1914 which created the fervor and subsequent European imports of birds called Araucanas.
From those original imports of Araucanas, breeders developed our modern recognized breeds, having taken a long and convoluted path rift with disagreements (and often dubious hybrid Easter Eggers) as to standards.
America follows the European standard with Araucanas that have been refined to retain the tufts and rumplessness. In America we also have the Ameraucana which bears the beard/muff and tail. Australia and Britain have a tailed, crested, and tufted Araucana (developed from a shipment of original Araucanas that were shipwrecked off the coast of Scotland).
These 3 breeds all stem from the original La Araucana, itself mixes of the Querto and Collona by the Mapuche tribe. I seriously doubt you'll find any remnants of those birds to breed from as the birds in modern Chile are predominantly very mixed, mostly from European domesticated stock or simply commercial hatchery birds.
So any landrace of which you speak to breed from would be descendants from the Araucana of La Araucana, which we call the Araucana and Ameraucana.
As the OP's bird has beard, willow legs, and is in America, it is reasonable to conjecture that it is from Ameraucana blood rather than Australian/British Araucana (muffed/tailed) blood. If it were from Araucana blood (assuming American strain), it would have no beard, possibly tufts (though those drop out quickly in generations), and yellow legs.
LofMc
http://ameraucanabreedersclub.org/history.html